实时数字图像无损压缩的研究

针对实时数字图像的无损压缩方法进行了分析,采用三级5-3整数提升小波变换,小波变换的高频和低频系数分别采用不同的编码方法。进行了基于DSP和FPGA的压缩系统结构设计,提出了软、硬件并行的方法。进行三级小波变换时,硬件结构能够实现在对当前级小波变换的同时进行前一级小波变换的高频系数编码,提高了压缩系统的实时性。并对压缩系统的关键技术进行了研究。可以对80MB/s的数字图像进行无损压缩,压缩比可以达到1.68~1.8左右。

Lossless image compression on real-time

The approaches of lossless digital image compression on real-time are analyzed.The 3 level 5-3 integer wavelet transform is adopted.The approach of lossless image compression based on prediction is used to low frequency sub-band,and the bit plane encoding to high frequency sub-band.The system of digital image compression based on DSP and FPGA is designed.The parallel ways both hard ware and software are also put forward.The key techniques are studied.The rate of input data can be up to 80MB/s.The compress ratio is between 1.68 and 1.8.